Do you think repeat offenders should be punished more harshly than first-time offenders for the same crime? Does it make any difference if I make it clear that the specific hypothetical crime in question has caused the same harm in each case? If you still think the repeat offender should be punished more harshly, you’re not alone. In fact this approach to justice is written into law in many countries. First time offenders can expect leniency whereas repeat offenders can expect severe punishment.

Why is it our moral intuition to take this stance? Dorit Kliemann and colleagues have tested the idea that it has to do with intentionality. If a repeat offender commits a crime, we are more likely to believe they did so intentionally than if a first-time offender commits the same act. The researchers argue this attribution of intentionality justifies our initial intuitive judgement that the repeat offender is more blameworthy.

Dozens of university students played an economic game against ten fictitious other students who were identified by a photograph (the participants were tricked into thinking these were real students enrolled in the same experiment). Some of these fictitious students played fairly whereas the others played selfishly. Later on the participants read stories about good or bad acts committed by those same students they’d played earlier. In the stories, intent was kept deliberately ambiguous.

Crucially, when the participants read about a bad act (e.g. shrinking a neighbour’s new sweater) committed by a previously unfair student, they were more likely to attribute blame and intent to that student, compared with when the same act was committed by a student who’d previously played fairly. Moreover, scans taken of the participants’ brains showed that a bad act committed by a previously unfair student led to greater activation of regions involved in attributing intentional states to others. The timing of this intent-related brain activity occurred after participants had decided how blameworthy the student was.

“One possibility,” the researchers said, “is that subjects first feel an impulse to blame previously unfair people for causing negative outcomes, and then subsequently seek to justify this impulse by attributing to them negative intentions.”

By contrast, when it came to good acts, a fictional students’ earlier fairness had no bearing on how the participants allocated intent, nor on how their brain responded to hearing about that good act._________________________________